diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-11-21 11:32:51 +0300 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-11-25 18:10:32 +0300 |
| commit | 2f9babc04d74cbf984f0cb5b6e20bd78fdf32997 (patch) | |
| tree | e1a94051f8deef64670cf7d5c5b8f072a6d01db4 | |
| parent | 3c1100f042c006cae6c241028cc4c69e1a70483f (diff) | |
| download | linux-2f9babc04d74cbf984f0cb5b6e20bd78fdf32997.tar.xz | |
net_sched: sch_fq: prefetch one skb ahead in dequeue()
prefetch the skb that we are likely to dequeue at the next dequeue().
Also call fq_dequeue_skb() a bit sooner in fq_dequeue().
This reduces the window between read of q.qlen and
changes of fields in the cache line that could be dirtied
by another cpu trying to queue a packet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-10-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/sched/sch_fq.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index 0b0ca1aa9251..6e5f2f4f2415 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -480,7 +480,10 @@ static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow, struct sk_buff *skb) { if (skb == flow->head) { - flow->head = skb->next; + struct sk_buff *next = skb->next; + + prefetch(next); + flow->head = next; } else { rb_erase(&skb->rbnode, &flow->t_root); skb->dev = qdisc_dev(sch); @@ -712,6 +715,7 @@ begin: goto begin; } prefetch(&skb->end); + fq_dequeue_skb(sch, f, skb); if ((s64)(now - time_next_packet - q->ce_threshold) > 0) { INET_ECN_set_ce(skb); q->stat_ce_mark++; @@ -719,7 +723,6 @@ begin: if (--f->qlen == 0) q->inactive_flows++; q->band_pkt_count[fq_skb_cb(skb)->band]--; - fq_dequeue_skb(sch, f, skb); } else { head->first = f->next; /* force a pass through old_flows to prevent starvation */ |